1. Field of the Invention
The present invention relates to a method of reducing the sulfur and nitrogen content of a hydrocarbon product; more particularly, the present invention relates to a method of reducing the sulfur and nitrogen content of a hydrocarbon product in the liquid or gaseous phase by contact with nahcolite.
2. Description of the Prior Art
The presence of sulfur and nitrogen in combustible hydrocarbon products has long been considered a serious pollution problem since the burning of the sulfur-containing hydrocarbon produces sulfur dioxide in the flue gas and the burning of the nitrogen-containing hydrocarbon produces nitrogen oxides(s). In fact, due to the SO.sub.2 and NO.sub.x (inclusive of NO and NO.sub.2) pollution created by the burning of the sulfur-containing and nitrogen-containing hydrocarbons, environmental standards have been set for the maximum impurity content permissible in certain combustible hydrocarbons, e.g., sulfur content in coal, and standards are planned for maximum NO.sub.x content in flue gases.
The attempts to eliminate the pollution problem have taken many forms. For example, various and sundry compositions have been developed for scrubbing the flue gas in a hydrocarbon combustion process, so as to effectively absorb the sulfur dioxide and NO.sub.x emissions in the flue gas. In addition, it has been proposed that the addition of chemicals to the hydrocarbon product prior to combustion can eliminate the problem of excessive sulfur dioxide or NO.sub.x emissions by either binding with the sulfur or nitrogen impurities to prevent sulfur dioxide or nitrogen oxide(s) formation in the combustion process or by absorption of the sulfur dioxide and NO.sub.x formed in the combustion process prior to allowing escape in the flue gas. For example, limestone has been proposed as one such additive, and, in the area of reduction of SO.sub.2 emissions from the combustion of coal, U.S. Pat. No. 3,823,676 to Cook suggests that naturally occurring Trona can serve this same function.
Contrary to these previous proposals, it has been discovered in accordance with the present invention that the sulfur and nitrogen content of a combustible hydrocarbon, and as a consequence, the sulfur dioxide and nitrogen oxides emissions upon combustion, can be reduced by contacting the hydrocarbon in the liquid or gaseous phase with an effective amount of nahcolite, a naturally occurring sodium bicarbonate, NaHCO.sub.3, the nahcolite being a white monoclinic mineral.